Washington State has experienced an epidemic increase in workers' compensation claims for occupational hearing loss. There is a need for actions to address and remediate the underlying problems, but there remains a critical need for information to guide any interventions in a constructive and efficient manner. The proposed research will build on the experience of a pilot project conducted by the State Department of Labor and Industries, and University of Washington studies of workers' compensation claims, to pursue three major long-term objectives: (1) To identify factors or phenomena that may have contributed to the recent increase in reporting of occupational hearing loss (OHL); (2) To determine if there is any substantial work-related risk at the present time for OHL among workers in industries that have experienced high rates of claims for hearing loss; and (3) To assess the effectiveness of approaches to interpreting workers' compensation claims data, for the purpose of "targeting" industries and worksites with remediable risk factors for an occupational health problem, using OHL as a case in point. The proposed research will be conducted at the University of Washington, in collaboration with researchers at the State Department of Labor and Industries (DLI). State workers' compensation claims data, representing nearly all of the non- federal worker population in the state, will be used as a foundation for three related projects: Project 1 is a descriptive analysis of data from the DLI Noise-Targeting Pilot Project; Project 2 is a cross-sectional study, using telephone interviews, of individuals with workers' compensation claims that were filed and accepted for occupational hearing loss within the preceding two calendar years; and Project 3 is a cross-sectional study, using structured, noise-focused evaluations of worksites in nine targeted industry categories. The proposed research will address these primary Study Questions: (1) What are the major "awareness- healthcare-claim pathways" by which individual persons with OHL are identified and reported to the workers' compensation system? (2) Using workers compensation data for OHL claims, can one identify industries that currently have substantial, remediable risk factors for OHL: (a) noise levels that exceed legal standards, (b) under-utilization of feasible noise controls, and (c) hearing conservation programs that are not compliant with legal standards and/or are not optimally effective?